Conventional electronic devices can receive user input from a keyboard. Generally, each key of a keyboard incorporates a dedicated electromechanical actuator that guides the mechanical movement of the depressible key, provides a tactile feedback to the user, and completes an electrical circuit when the depressible key is pressed.
Typically, an electromechanical actuator is formed as a multi-part apparatus including a travel mechanism, a tactile feedback structure, a common contact, and a pair of electrical traces. In many cases, the travel mechanism can be implemented as a scissor or butterfly mechanism that is configured to collapse along an axis. The tactile feedback structure can be implemented as a compressible dome, made from a material such as metal, plastic, or an elastomer. The common contact can be implemented as an electrically conductive material such as metal or a metal-doped polymer. The pair of electrical traces may be disposed on a substrate positioned below a keycap.
For many conventional electromechanical actuators, the travel mechanism is coupled to and positioned centrally below the keycap, the tactile feedback structure is nested within the travel mechanism below the keycap, and the common contact is coupled to the feedback structure and positioned over the electrical traces. By applying a downward force to the keycap, the travel mechanism and tactile feedback structure temporarily deform and collapse, thereby wetting the common contact to the electrical traces so as to complete a circuit to indicate a depressible key press to the electronic device.
The components of a conventional electromechanical actuator are often specifically aligned to the geometric center of the keycap in order to provide a consistent and reliable electrical connection upon depression of the depressible key. One may appreciate therefore, that as a result of nesting and alignment, the dimensions of each component of the conventional electromechanical actuator may be limited, fixed, influenced, and/or defined by one or more dimensions of other components within the stack. For example, the electrical sensitivity of the depressible key may depend upon the overlapping surface area of the electrical contacts and the common contact, which in turn may depend upon the size of the tactile feedback structure, which in turn may depend upon the inner dimensions of the travel mechanism, which in turn may depend upon the dimensions of the keycap, which in turn may be defined by the size and shape of the keyboard.
Furthermore, certain users may prefer certain keyboards (and/or keys) to have specific electromechanical properties. For example, certain users may prefer to type with rigid and deep keys whereas other users may prefer to type with spongy and short keys.
However, customizing the typing experience of a keyboard for a particular user requires modification of multiple components of each electromechanical actuator specifically because the electrical, tactile, and mechanical functionality of the depressible key are tightly coupled and interdependent. For example, independently increasing the rigidity of the tactile feedback structure can affect the user's perception of both press sensitivity and key stiffness. As a result, enhancing and/or refining characteristics of the user's typing experience on a keyboard conventionally involves alteration of multiple materials, multiple structures, and multiple couplings which, in turn, increases the time and cost associated with research and development, prototyping, re-tooling, and manufacturing of keys and keyboards.
Accordingly, there may be a present need for systems and methods for decoupling the mechanical and tactile functionality of depressible keys from the electrical functionality of depressible keys.